code: def _flatten(ll: list) -> list:
      ret = []
      for i in ll:
          if isinstance(i, list):
              ret.extend(_flatten(i))
          else:
              ret.append(i)
      return ret
  
imports: import inspect
  import warnings
  import types
  import collections
  import itertools
  from functools import lru_cache, wraps
  from typing import Callable, List, Union, Iterable, TypeVar, cast
label_desc: Use image node_id 6 for calling a global function with example usage: _flatten(ll) and returns: ret